(* $Id: index.mli 9822 2009-06-03 15:37:06Z tassi $ *)
-module Superposition (B : Terms.Blob) =
+module Superposition (B : Orderings.Blob) =
struct
module IDX = Index.Index(B)
- module Unif = FoUnif.Founif(B)
- module Subst = FoSubst.Subst(B)
- module Order = Orderings.Orderings(B)
+ module Unif = FoUnif.FoUnif(B)
+ module Subst = FoSubst
+ module Order = B
module Utils = FoUtils.Utils(B)
module Pp = Pp.Pp(B)
+ module Clauses = Clauses.Clauses(B)
- exception Success of B.t Terms.bag * int * B.t Terms.unit_clause
+ exception Success of B.t Terms.bag * int * B.t Terms.clause
- let debug s =
- ()(* prerr_endline s *)
- ;;
+ let debug s = prerr_endline (Lazy.force s);;
+ (* let debug _ = ();; *)
+ let enable = true;;
let rec list_first f = function
| [] -> None
;;
let first_position pos ctx t f =
+ let inject_pos pos ctx = function
+ | None -> None
+ | Some (a,b,c,d) -> Some(ctx a,b,c,d,pos)
+ in
let rec aux pos ctx = function
- | Terms.Leaf _ as t -> f t pos ctx
+ | Terms.Leaf _ as t -> inject_pos pos ctx (f t)
| Terms.Var _ -> None
- | Terms.Node l as t->
- match f t pos ctx with
- | Some _ as x -> x
+ | Terms.Node l as t->
+ match f t with
+ | Some _ as x -> inject_pos pos ctx x
| None ->
let rec first pre post = function
| [] -> None
in
aux pos ctx t
;;
+
+ let parallel_positions bag pos ctx id lit t f =
+ let rec aux bag pos ctx id lit = function
+ | Terms.Leaf _ as t -> f bag t pos ctx id lit
+ | Terms.Var _ as t -> bag,t,id,lit
+ | Terms.Node (hd::l) as t->
+ let bag,t,id1,lit = f bag t pos ctx id lit in
+ if id = id1 then
+ let bag, l, _, id, lit =
+ List.fold_left
+ (fun (bag,pre,post,id,lit) t ->
+ let newctx = fun x -> ctx (Terms.Node (pre@[x]@post)) in
+ let newpos = (List.length pre)::pos in
+ let bag,newt,id,lit = aux bag newpos newctx id lit t in
+ if post = [] then bag, pre@[newt], [], id,lit
+ else bag, pre @ [newt], List.tl post, id, lit)
+ (bag, [hd], List.tl l, id,lit) l
+ in
+ bag, Terms.Node l, id, lit
+ else bag,t,id1,lit
+ | _ -> assert false
+ in
+ aux bag pos ctx id lit t
+ ;;
- let build_clause bag filter rule t subst vl id id2 pos dir =
+ let build_clause bag filter rule t subst id id2 pos dir clause_ctx =
let proof = Terms.Step(rule,id,id2,dir,pos,subst) in
let t = Subst.apply_subst subst t in
- if filter t then
+ if filter subst then
let literal =
match t with
| Terms.Node [ Terms.Leaf eq ; ty; l; r ] when B.eq B.eqP eq ->
Terms.Equation (l, r, ty, o)
| t -> Terms.Predicate t
in
+ let nlit,plit = clause_ctx literal in
let bag, uc =
- Utils.add_to_bag bag (0, literal, vl, proof)
+ Terms.add_to_bag (0, nlit, plit, Terms.vars_of_term t, proof) bag
in
- Some (bag, uc)
+ Some (bag, uc, literal)
else
((*prerr_endline ("Filtering: " ^ Pp.pp_foterm t);*)None)
;;
+ let prof_build_clause = HExtlib.profile ~enable "build_clause";;
+ let build_clause bag filter rule t subst id id2 pos x =
+ prof_build_clause.HExtlib.profile (build_clause bag filter rule t subst id id2 pos) x
+ ;;
(* ============ simplification ================= *)
+ let prof_demod_u = HExtlib.profile ~enable "demod.unify";;
+ let prof_demod_r = HExtlib.profile ~enable "demod.retrieve_generalizations";;
+ let prof_demod_o = HExtlib.profile ~enable "demod.compare_terms";;
+ let prof_demod_s = HExtlib.profile ~enable "demod.apply_subst";;
- let demod table varlist subterm pos context =
- let cands = IDX.DT.retrieve_generalizations table subterm in
+ let demod table varlist subterm =
+ let cands =
+ prof_demod_r.HExtlib.profile
+ (IDX.DT.retrieve_generalizations table) subterm
+ in
list_first
- (fun (dir, (id,lit,vl,_)) ->
- match lit with
- | Terms.Predicate _ -> assert false
- | Terms.Equation (l,r,_,o) ->
- let side, newside = if dir=Terms.Left2Right then l,r else r,l in
- try
- let subst, varlist =
- Unif.unification (varlist@vl) varlist subterm side
- in
- if o = Terms.Incomparable then
- let side = Subst.apply_subst subst side in
- let newside = Subst.apply_subst subst newside in
- let o = Order.compare_terms newside side in
- (* Riazanov, pp. 45 (ii) *)
- if o = Terms.Lt then
- Some (context newside, subst, varlist, id, pos, dir)
- else
- ((*prerr_endline ("Filtering: " ^
- Pp.pp_foterm side ^ " =(< || =)" ^
- Pp.pp_foterm newside ^ " coming from " ^
- Pp.pp_unit_clause uc );*)None)
- else
- Some (context newside, subst, varlist, id, pos, dir)
- with FoUnif.UnificationFailure _ -> None)
- (IDX.ClauseSet.elements cands)
+ (fun (dir, is_pos, pos, (id,nlit,plit,vl,_)) ->
+ match nlit,plit with
+ | [], [(lit,_)] ->
+ (match lit with
+ | Terms.Predicate _ -> assert false
+ | Terms.Equation (l,r,_,o) ->
+ let side, newside = if dir=Terms.Left2Right then l,r else r,l in
+ try
+ let subst =
+ prof_demod_u.HExtlib.profile
+ (Unif.unification (* (varlist@vl) *) varlist subterm) side
+ in
+ let side =
+ prof_demod_s.HExtlib.profile
+ (Subst.apply_subst subst) side
+ in
+ let newside =
+ prof_demod_s.HExtlib.profile
+ (Subst.apply_subst subst) newside
+ in
+ if o = Terms.Incomparable || o = Terms.Invertible then
+ let o =
+ prof_demod_o.HExtlib.profile
+ (Order.compare_terms newside) side in
+ (* Riazanov, pp. 45 (ii) *)
+ if o = Terms.Lt then
+ Some (newside, subst, id, dir)
+ else
+ ((*prerr_endline ("Filtering: " ^
+ Pp.pp_foterm side ^ " =(< || =)" ^
+ Pp.pp_foterm newside ^ " coming from " ^
+ Pp.pp_clause uc );*)None)
+ else
+ Some (newside, subst, id, dir)
+ with FoUnif.UnificationFailure _ -> None)
+ | _ -> None)
+ (IDX.ClauseSet.elements cands)
+ ;;
+ let prof_demod = HExtlib.profile ~enable "demod";;
+ let demod table varlist x =
+ prof_demod.HExtlib.profile (demod table varlist) x
+ ;;
+
+ let parallel_demod table vl clause_ctx bag t pos ctx id lit =
+ match demod table vl t with
+ | None -> (bag,t,id,lit)
+ | Some (newside, subst, id2, dir) ->
+ match build_clause bag (fun _ -> true)
+ Terms.Demodulation (ctx newside) subst id id2 pos dir clause_ctx
+ with
+ | None -> assert false
+ | Some (bag,(id,_,_,_,_),lit) ->
+ (bag,newside,id,lit)
;;
- (* XXX: possible optimization, if the literal has a "side" already
- * in normal form we should not traverse it again *)
- let demodulate_once bag (id, literal, vl, pr) table =
- debug ("Demodulating : " ^ (Pp.pp_unit_clause (id, literal, vl, pr)));
- let t =
- match literal with
- | Terms.Predicate t -> t
- | Terms.Equation (l,r,ty,_) -> Terms.Node [ Terms.Leaf B.eqP; ty; l; r ]
+ let demodulate_once ~jump_to_right bag id literal vl table clause_ctx =
+ match literal with
+ | Terms.Predicate t -> assert false
+ | Terms.Equation (l,r,ty,_) as lit ->
+ let bag,l,id1,lit = if jump_to_right then (bag,l,id,lit) else
+ parallel_positions bag [2]
+ (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ]) id lit l
+ (parallel_demod table vl clause_ctx)
+ in
+ let jump_to_right = id1 = id in
+ let bag,r,id2,lit =
+ parallel_positions bag [3]
+ (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ]) id1 lit r
+ (parallel_demod table vl clause_ctx)
+ in
+ if id = id2 then None
+ else
+ Some ((bag,id2,lit),jump_to_right)
+ ;;
+
+ let rec demodulate bag (id,nlit,plit,vl,proof) table =
+ let rec demod_lit ~jump_to_right bag id lit clause_ctx =
+ match demodulate_once ~jump_to_right bag id lit vl table clause_ctx with
+ | None -> bag, id, lit
+ | Some ((bag, id, lit),jump) ->
+ demod_lit ~jump_to_right:jump bag id lit clause_ctx
in
- match first_position [] (fun x -> x) t (demod table vl) with
- | None -> None
- | Some (newt, subst, varlist, id2, pos, dir) ->
- build_clause bag (fun _ -> true) Terms.Demodulation
- newt subst varlist id id2 pos dir
+ (*let cmp_bag,cmp_cl = match nlit,plit with
+ |[],[lit,_] ->
+ let bag, id, lit = demod_lit ~jump_to_right:false bag id lit (fun l -> nlit, [l,true])
+ in
+ let cl,_,_ = Terms.get_from_bag id bag in
+ bag,cl
+ |[lit,_],[] ->
+ let bag, id, lit = demod_lit ~jump_to_right:false bag id lit (fun l -> [l,true],[])
+ in
+ let cl,_,_ = Terms.get_from_bag id bag in
+ bag,cl
+ |_ -> assert false
+ in*)
+ let nlit,_,bag,id = if nlit = [] then nlit,[],bag,id
+ else List.fold_left
+ (fun (pre,post,bag,id) (lit,sel) ->
+ let bag, id, lit =
+ demod_lit ~jump_to_right:false bag id lit (fun l -> pre@[l,sel]@post,plit)
+ in
+ if post=[] then pre@[(lit,sel)],[],bag,id
+ else pre@[(lit,sel)],List.tl post,bag,id)
+ ([],List.tl nlit, bag, id) nlit
+ in
+ let _,_,bag,id = if plit = [] then plit,[],bag,id
+ else List.fold_left
+ (fun (pre,post,bag,id) (lit,sel) ->
+ let bag, id, lit =
+ demod_lit ~jump_to_right:false bag id lit (fun l -> nlit,pre@[l,sel]@post)
+ in
+ if post=[] then pre@[(lit,sel)],[],bag,id
+ else pre@[(lit,sel)],List.tl post,bag,id)
+ ([],List.tl plit, bag, id) plit
+ in
+ let cl,_,_ = Terms.get_from_bag id bag in
+ bag,cl
;;
- let rec demodulate bag clause table =
- match demodulate_once bag clause table with
- | None -> bag, clause
- | Some (bag, clause) -> demodulate bag clause table
+ let prof_demodulate = HExtlib.profile ~enable "demodulate";;
+ let demodulate bag clause x =
+ prof_demodulate.HExtlib.profile (demodulate bag clause) x
;;
(* move away *)
- let is_identity_clause = function
- | _, Terms.Equation (_,_,_,Terms.Eq), _, _ -> true
- | _, Terms.Predicate _, _, _ -> assert false
+ let is_identity_clause ~unify = function
+ | _, [], [Terms.Equation (_,_,_,Terms.Eq),_], _, _ -> true
+ | _, [], [Terms.Equation (l,r,_,_),_], vl, _ when unify ->
+ (try ignore(Unif.unification (* vl *) [] l r); true
+ with FoUnif.UnificationFailure _ -> false)
| _ -> false
;;
- let is_subsumed ~unify (id, lit, vl, _) table =
- match lit with
- | Terms.Predicate _ -> assert false
- | Terms.Equation (l,r,ty,_) ->
- let retrieve = if unify then IDX.DT.retrieve_unifiables
- else IDX.DT.retrieve_generalizations in
- let lcands = retrieve table l in
- let rcands = retrieve table r in
- let f b c =
- let dir, l, r, vl =
- match c with
- | (d, (_,Terms.Equation (l,r,ty,_),vl,_))-> d, l, r, vl
- |_ -> assert false
- in
- let l, r = if (dir = Terms.Left2Right) = b then l,r else r,l in
- Terms.Node [ Terms.Leaf B.eqP; ty; l; r ], vl
- in
- let cands1 = List.map (f true) (IDX.ClauseSet.elements lcands) in
- let cands2 = List.map (f false) (IDX.ClauseSet.elements rcands) in
- let t = Terms.Node [ Terms.Leaf B.eqP; ty; l; r ] in
- let locked_vars = if unify then [] else vl in
- List.exists
- (fun (c, vl1) ->
- try ignore(Unif.unification (vl@vl1) locked_vars c t); true
- with FoUnif.UnificationFailure _ -> false)
- (cands1 @ cands2)
+ let is_goal_trivial = function
+ | _, [Terms.Equation (_,_,_,Terms.Eq),_], [], _, _ -> true
+ | _, [Terms.Equation (l,r,_,_),_], [], vl, _ ->
+ (try ignore(Unif.unification (* vl *) [] l r); true
+ with FoUnif.UnificationFailure _ -> false)
+ | _ -> false
+
+ let build_new_clause bag maxvar filter rule t subst id id2 pos dir =
+ let maxvar, _vl, subst = Utils.relocate maxvar (Terms.vars_of_term
+ (Subst.apply_subst subst t)) subst in
+ match build_clause bag filter rule t subst id id2 pos dir (fun x -> [],[(x,true)]) with
+ | Some (bag, c, _) -> Some ((bag, maxvar), c)
+ | None -> None
+ ;;
+ let prof_build_new_clause = HExtlib.profile ~enable "build_new_clause";;
+ let build_new_clause bag maxvar filter rule t subst id id2 pos x =
+ prof_build_new_clause.HExtlib.profile (build_new_clause bag maxvar filter
+ rule t subst id id2 pos) x
+ ;;
+
+ let fold_build_new_clause bag maxvar id rule filter res =
+ let (bag, maxvar), res =
+ HExtlib.filter_map_acc
+ (fun (bag, maxvar) (t,subst,id2,pos,dir) ->
+ build_new_clause bag maxvar filter rule t subst id id2 pos dir)
+ (bag, maxvar) res
+ in
+ bag, maxvar, res
+ ;;
+
+ (* Tries to rewrite an equality to identity, using unit equalities in table *)
+ let rewrite_eq ~unify l r ty vl table =
+ let retrieve = if unify then IDX.DT.retrieve_unifiables
+ else IDX.DT.retrieve_generalizations in
+ let lcands = retrieve table l in
+ let rcands = retrieve table r in
+ let f b c =
+ let id, dir, l, r, vl =
+ match c with
+ | (d,_,_, (id,[],[Terms.Equation (l,r,ty,_),_],vl,_))-> id, d, l, r, vl
+ | (d,_,_, (id,[Terms.Equation (l,r,ty,_),_],[],vl,_))-> id, d, l, r, vl
+ |_ -> assert false
+ in
+ let reverse = (dir = Terms.Left2Right) = b in
+ let l, r, proof_rewrite_dir = if reverse then l,r,Terms.Left2Right
+ else r,l, Terms.Right2Left in
+ (id,proof_rewrite_dir,Terms.Node [ Terms.Leaf B.eqP; ty; l; r ], vl)
+ in
+ let cands1 = List.map (f true) (IDX.ClauseSet.elements lcands) in
+ let cands2 = List.map (f false) (IDX.ClauseSet.elements rcands) in
+ let t = Terms.Node [ Terms.Leaf B.eqP; ty; l; r ] in
+ let locked_vars = if unify then [] else vl in
+ let rec aux = function
+ | [] -> None
+ | (id2,dir,c,vl1)::tl ->
+ try
+ let subst = Unif.unification (* (vl@vl1) *) locked_vars c t in
+ Some (id2, dir, subst)
+ with FoUnif.UnificationFailure _ -> aux tl
+ in
+ aux (cands1 @ cands2)
+ ;;
+
+ let is_subsumed ~unify bag maxvar (id, nlit, plit, vl, _) table =
+ match nlit,plit with
+ | [],[Terms.Equation (l,r,ty,_) ,_]->
+ (match rewrite_eq ~unify l r ty vl table with
+ | None -> None
+ | Some (id2, dir, subst) ->
+ let id_t = Terms.Node [ Terms.Leaf B.eqP; ty; r; r ] in
+ build_new_clause bag maxvar (fun _ -> true)
+ Terms.Superposition id_t subst id id2 [2] dir)
+ | _ -> None (* TODO : implement subsumption for clauses *)
+ ;;
+ let prof_is_subsumed = HExtlib.profile ~enable "is_subsumed";;
+ let is_subsumed ~unify bag maxvar c x =
+ prof_is_subsumed.HExtlib.profile (is_subsumed ~unify bag maxvar c) x
+ ;;
+ (* id refers to a clause proving contextl l = contextr r *)
+
+ let rec deep_eq ~unify l r ty pos contextl contextr table acc =
+ match acc with
+ | None -> None
+ | Some(bag,maxvar,(id,nlit,plit,vl,p),subst) ->
+ let l = Subst.apply_subst subst l in
+ let r = Subst.apply_subst subst r in
+ try
+ let subst1 = Unif.unification (* vl *) [] l r in
+ let lit =
+ match nlit,plit with
+ | [],[Terms.Equation (l,r,ty,o),_] ->
+ Terms.Equation (FoSubst.apply_subst subst1 l,
+ FoSubst.apply_subst subst1 r, ty, o)
+ | _ -> assert false
+ in
+ Some(bag,maxvar,(id,[],[lit,true],vl,p),Subst.concat subst1 subst)
+ with FoUnif.UnificationFailure _ ->
+ match rewrite_eq ~unify l r ty vl table with
+ | Some (id2, dir, subst1) ->
+ let newsubst = Subst.concat subst1 subst in
+ let id_t =
+ FoSubst.apply_subst newsubst
+ (Terms.Node[Terms.Leaf B.eqP;ty;contextl r;contextr r])
+ in
+ (match
+ build_new_clause bag maxvar (fun _ -> true)
+ Terms.Superposition id_t
+ subst1 id id2 (pos@[2]) dir
+ with
+ | Some ((bag, maxvar), c) ->
+ Some(bag,maxvar,c,newsubst)
+ | None -> assert false)
+ | None ->
+ match l,r with
+ | Terms.Node (a::la), Terms.Node (b::lb) when
+ a = b && List.length la = List.length lb ->
+ let acc,_,_,_ =
+ List.fold_left2
+ (fun (acc,pre,postl,postr) a b ->
+ let newcl =
+ fun x -> contextl(Terms.Node (pre@(x::postl))) in
+ let newcr =
+ fun x -> contextr(Terms.Node (pre@(x::postr))) in
+ let newpos = List.length pre::pos in
+ let footail l =
+ if l = [] then [] else List.tl l in
+ (deep_eq ~unify a b ty
+ newpos newcl newcr table acc,pre@[b],
+ footail postl, footail postr))
+ (acc,[a],List.tl la,List.tl lb) la lb
+ in acc
+ | _,_ -> None
+ ;;
+ let prof_deep_eq = HExtlib.profile ~enable "deep_eq";;
+ let deep_eq ~unify l r ty pos contextl contextr table x =
+ prof_deep_eq.HExtlib.profile (deep_eq ~unify l r ty pos contextl contextr table) x
+ ;;
+
+ let rec orphan_murder bag acc i =
+ match Terms.get_from_bag i bag with
+ | (_,_,_,_,Terms.Exact _),discarded,_ -> (discarded,acc)
+ | (_,_,_,_,Terms.Step (_,i1,i2,_,_,_)),true,_ -> (true,acc)
+ | (_,_,_,_,Terms.Step (_,i1,i2,_,_,_)),false,_ ->
+ if (List.mem i acc) then (false,acc)
+ else match orphan_murder bag acc i1 with
+ | (true,acc) -> (true,acc)
+ | (false,acc) ->
+ let (res,acc) = orphan_murder bag acc i2 in
+ if res then res,acc else res,i::acc
+ ;;
+
+ let orphan_murder bag actives cl =
+ let (id,_,_,_,_) = cl in
+ let actives = List.map (fun (i,_,_,_,_) -> i) actives in
+ let (res,_) = orphan_murder bag actives id in
+ if res then debug (lazy "Orphan murdered"); res
+ ;;
+ let prof_orphan_murder = HExtlib.profile ~enable "orphan_murder";;
+ let orphan_murder bag actives x =
+ prof_orphan_murder.HExtlib.profile (orphan_murder bag actives) x
;;
(* demodulate and check for subsumption *)
- let forward_simplify table bag clause =
- let bag, clause = demodulate bag clause table in
- if is_identity_clause clause then None
+ let simplify table maxvar bag clause =
+ if is_identity_clause ~unify:false clause then bag,None
+ (* else if orphan_murder bag actives clause then bag,None *)
+ else let bag, clause = demodulate bag clause table in
+ if is_identity_clause ~unify:false clause then bag,None
else
- if is_subsumed ~unify:false clause table then None
- else Some (bag, clause)
+ match is_subsumed ~unify:false bag maxvar clause table with
+ | None -> bag, Some clause
+ | Some _ -> bag, None
+ ;;
+
+ let simplify table maxvar bag clause =
+ match simplify table maxvar bag clause with
+ | bag, None ->
+ let (id,_,_,_,_) = clause in
+ let (_,_,iter) = Terms.get_from_bag id bag in
+ Terms.replace_in_bag (clause,true,iter) bag, None
+ | bag, Some clause -> bag, Some clause
+ (*let (id,_,_,_) = clause in
+ if orphan_murder bag clause then
+ Terms.M.add id (clause,true) bag, Some clause
+ else bag, Some clause*)
+ ;;
+ let prof_simplify = HExtlib.profile ~enable "simplify";;
+ let simplify table maxvar bag x =
+ prof_simplify.HExtlib.profile (simplify table maxvar bag ) x
+ ;;
+
+ let one_pass_simplification new_clause (alist,atable) bag maxvar =
+ match simplify atable maxvar bag new_clause with
+ | bag,None -> bag,None (* new_clause has been discarded *)
+ | bag,(Some clause) ->
+ let ctable = IDX.index_clause IDX.DT.empty clause in
+ let bag, alist, atable =
+ List.fold_left
+ (fun (bag, alist, atable) c ->
+ match simplify ctable maxvar bag c with
+ |bag,None -> (bag,alist,atable)
+ (* an active clause as been discarded *)
+ |bag,Some c1 ->
+ bag, c :: alist, IDX.index_clause atable c)
+ (bag,[],IDX.DT.empty) alist
+ in
+ bag, Some (clause, (alist,atable))
+ ;;
+ let prof_one_pass_simplification = HExtlib.profile ~enable "one_pass_simplification";;
+ let one_pass_simplification new_clause t bag x =
+ prof_one_pass_simplification.HExtlib.profile (one_pass_simplification new_clause t bag ) x
+ ;;
+
+ let simplification_step ~new_cl cl (alist,atable) bag maxvar new_clause =
+ let atable1 =
+ if new_cl then atable else
+ IDX.index_clause atable cl
+ in
+ (* Simplification of new_clause with : *
+ * - actives and cl if new_clause is not cl *
+ * - only actives otherwise *)
+ match
+ simplify atable1 maxvar bag new_clause with
+ | bag,None -> bag,(Some cl, None) (* new_clause has been discarded *)
+ | bag,Some clause ->
+ (* Simplification of each active clause with clause *
+ * which is the simplified form of new_clause *)
+ let ctable = IDX.index_clause IDX.DT.empty clause in
+ let bag, newa, alist, atable =
+ List.fold_left
+ (fun (bag, newa, alist, atable) c ->
+ match simplify ctable maxvar bag c with
+ |bag,None -> (bag, newa, alist, atable)
+ (* an active clause as been discarded *)
+ |bag,Some c1 ->
+ if (c1 == c) then
+ bag, newa, c :: alist,
+ IDX.index_clause atable c
+ else
+ bag, c1 :: newa, alist, atable)
+ (bag,[],[],IDX.DT.empty) alist
+ in
+ if new_cl then
+ bag, (Some cl, Some (clause, (alist,atable), newa))
+ else
+ (* if new_clause is not cl, we simplify cl with clause *)
+ match simplify ctable maxvar bag cl with
+ | bag,None ->
+ (* cl has been discarded *)
+ bag,(None, Some (clause, (alist,atable), newa))
+ | bag,Some cl1 ->
+ bag,(Some cl1, Some (clause, (alist,atable), newa))
+ ;;
+ let prof_simplification_step = HExtlib.profile ~enable "simplification_step";;
+ let simplification_step ~new_cl cl (alist,atable) bag maxvar x =
+ prof_simplification_step.HExtlib.profile (simplification_step ~new_cl cl (alist,atable) bag maxvar) x
+ ;;
+
+ let keep_simplified cl (alist,atable) bag maxvar =
+ let rec keep_simplified_aux ~new_cl cl (alist,atable) bag newc =
+ if new_cl then
+ match simplification_step ~new_cl cl (alist,atable) bag maxvar cl with
+ | _,(None, _) -> assert false
+ | bag,(Some _, None) -> bag,None
+ | bag,(Some _, Some (clause, (alist,atable), newa)) ->
+ keep_simplified_aux ~new_cl:(cl!=clause) clause (alist,atable)
+ bag (newa@newc)
+ else
+ match newc with
+ | [] -> bag, Some (cl, (alist,atable))
+ | hd::tl ->
+ match simplification_step ~new_cl cl
+ (alist,atable) bag maxvar hd with
+ | _,(None,None) -> assert false
+ | bag,(Some _,None) ->
+ keep_simplified_aux ~new_cl cl (alist,atable) bag tl
+ | bag,(None, Some _) -> bag,None
+ | bag,(Some cl1, Some (clause, (alist,atable), newa)) ->
+ let alist,atable =
+ (clause::alist, IDX.index_clause atable clause)
+ in
+ keep_simplified_aux ~new_cl:(cl!=cl1) cl1 (alist,atable)
+ bag (newa@tl)
+ in
+ keep_simplified_aux ~new_cl:true cl (alist,atable) bag []
+ ;;
+ let prof_keep_simplified = HExtlib.profile ~enable "keep_simplified";;
+ let keep_simplified cl t bag x =
+ prof_keep_simplified.HExtlib.profile (keep_simplified cl t bag) x
;;
- (* this is like forward_simplify but raises Success *)
- let backward_simplify maxvar table bag clause =
- let bag, clause = demodulate bag clause table in
- if (is_identity_clause clause) || (is_subsumed ~unify:true clause table)
+ (* this is like simplify but raises Success *)
+ let simplify_goal ~no_demod maxvar table bag g_actives clause =
+ let bag, clause =
+ if no_demod then bag, clause else demodulate bag clause table
+ in
+ if List.exists (Clauses.are_alpha_eq_cl clause) g_actives then None else
+ (debug (lazy (Pp.pp_clause clause));
+ if (is_goal_trivial clause)
then raise (Success (bag, maxvar, clause))
- else bag, clause
+ else
+ let (id,nlit,plit,vl,_) = clause in
+ if vl = [] then Some (bag,clause)
+ else
+ let l,r,ty =
+ match nlit,plit with
+ | [Terms.Equation(l,r,ty,_),_],[] -> l,r,ty
+ | _ -> assert false
+ in
+ match deep_eq ~unify:true l r ty [] (fun x -> x) (fun x -> x)
+ table (Some(bag,maxvar,clause,Subst.id_subst)) with
+ | None -> Some (bag,clause)
+ | Some (bag,maxvar,cl,subst) ->
+ prerr_endline "Goal subsumed";
+ raise (Success (bag,maxvar,cl)))
+(*
+ else match is_subsumed ~unify:true bag maxvar clause table with
+ | None -> Some (bag, clause)
+ | Some ((bag,maxvar),c) ->
+ prerr_endline "Goal subsumed";
+ raise (Success (bag,maxvar,c))
+*)
+ ;;
+
+ let prof_simplify_goal = HExtlib.profile ~enable "simplify_goal";;
+ let simplify_goal ~no_demod maxvar table bag g_actives x =
+ prof_simplify_goal.HExtlib.profile ( simplify_goal ~no_demod maxvar table bag g_actives) x
;;
(* =================== inference ===================== *)
let superposition table varlist subterm pos context =
let cands = IDX.DT.retrieve_unifiables table subterm in
HExtlib.filter_map
- (fun (dir, (id,lit,vl,_ (*as uc*))) ->
- match lit with
- | Terms.Predicate _ -> assert false
- | Terms.Equation (l,r,_,o) ->
- let side, newside = if dir=Terms.Left2Right then l,r else r,l in
+ (fun (dir, _, _, (id,nlit,plit,vl,_ (*as uc*))) ->
+ match nlit,plit with
+ | [],[Terms.Equation (l,r,_,o),_] ->
+ (let side, newside = if dir=Terms.Left2Right then l,r else r,l in
try
- let subst, varlist =
- Unif.unification (varlist@vl) [] subterm side
- in
- if o = Terms.Incomparable then
+ let subst =
+ Unif.unification (* (varlist@vl)*) [] subterm side
+ in
+ if o = Terms.Incomparable || o = Terms.Invertible then
let side = Subst.apply_subst subst side in
let newside = Subst.apply_subst subst newside in
let o = Order.compare_terms side newside in
(* XXX: check Riazanov p. 33 (iii) *)
if o <> Terms.Lt && o <> Terms.Eq then
- Some (context newside, subst, varlist, id, pos, dir)
+ Some (context newside, subst, id, pos, dir)
else
((*prerr_endline ("Filtering: " ^
Pp.pp_foterm side ^ " =(< || =)" ^
- Pp.pp_foterm newside ^ " coming from " ^
- Pp.pp_unit_clause uc );*)None)
+ Pp.pp_foterm newside);*)None)
else
- Some (context newside, subst, varlist, id, pos, dir)
+ Some (context newside, subst, id, pos, dir)
with FoUnif.UnificationFailure _ -> None)
+ | _ -> assert false)
(IDX.ClauseSet.elements cands)
;;
- let build_new_clause bag maxvar filter rule t subst vl id id2 pos dir =
- let maxvar, vl, relocsubst = Utils.relocate maxvar vl in
- let subst = Subst.concat relocsubst subst in
- match build_clause bag filter rule t subst vl id id2 pos dir with
- | Some (bag, c) -> Some ((bag, maxvar), c)
- | None -> None
- ;;
-
-
- let fold_build_new_clause bag maxvar id rule filter res =
- let (bag, maxvar), res =
- HExtlib.filter_map_acc
- (fun (bag, maxvar) (t,subst,vl,id2,pos,dir) ->
- build_new_clause bag maxvar filter rule t subst vl id id2 pos dir)
- (bag, maxvar) res
- in
- bag, maxvar, res
- ;;
-
(* Superposes selected equation with equalities in table *)
- let superposition_with_table bag maxvar (id,selected,vl,_) table =
- match selected with
- | Terms.Predicate _ -> assert false
- | Terms.Equation (l,r,ty,Terms.Lt) ->
+ let superposition_with_table bag maxvar (id,nlit,plit,vl,_) table =
+ match nlit,plit with
+ | [],[Terms.Equation (l,r,ty,Terms.Lt),_] ->
fold_build_new_clause bag maxvar id Terms.Superposition
(fun _ -> true)
(all_positions [3]
(fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
- r (superposition table vl))
- | Terms.Equation (l,r,ty,Terms.Gt) ->
+ r (superposition table vl))
+ | [],[Terms.Equation (l,r,ty,Terms.Invertible),_]
+ | [],[Terms.Equation (l,r,ty,Terms.Gt),_] ->
fold_build_new_clause bag maxvar id Terms.Superposition
(fun _ -> true)
(all_positions [2]
(fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ])
l (superposition table vl))
- | Terms.Equation (l,r,ty,Terms.Incomparable) ->
- fold_build_new_clause bag maxvar id Terms.Superposition
- (function (* Riazanov: p.33 condition (iv) *)
- | Terms.Node [Terms.Leaf eq; ty; l; r ] when B.eq B.eqP eq ->
- Order.compare_terms l r <> Terms.Eq
- | _ -> assert false)
- ((all_positions [3]
- (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
- r (superposition table vl)) @
- (all_positions [2]
- (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ])
- l (superposition table vl)))
+ | [],[Terms.Equation (l,r,ty,Terms.Incomparable),_] ->
+ let filtering avoid subst = (* Riazanov: p.33 condition (iv) *)
+ let l = Subst.apply_subst subst l in
+ let r = Subst.apply_subst subst r in
+ let o = Order.compare_terms l r in
+ o <> avoid && o <> Terms.Eq
+ in
+ let bag, maxvar,r_terms =
+ fold_build_new_clause bag maxvar id Terms.Superposition
+ (filtering Terms.Gt)
+ (all_positions [3]
+ (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; l; x ])
+ r (superposition table vl))
+ in
+ let bag, maxvar, l_terms =
+ fold_build_new_clause bag maxvar id Terms.Superposition
+ (filtering Terms.Lt)
+ (all_positions [2]
+ (fun x -> Terms.Node [ Terms.Leaf B.eqP; ty; x; r ])
+ l (superposition table vl))
+ in
+ bag, maxvar, r_terms @ l_terms
| _ -> assert false
;;
(* the current equation is normal w.r.t. demodulation with atable
* (and is not the identity) *)
let infer_right bag maxvar current (alist,atable) =
- (* We demodulate actives clause with current *)
- let ctable = IDX.index_unit_clause IDX.DT.empty current in
- let bag, (alist, atable) =
+ (* We demodulate actives clause with current until all *
+ * active clauses are reduced w.r.t each other *)
+ (* let bag, (alist,atable) = keep_simplified (alist,atable) bag [current] in *)
+ let ctable = IDX.index_clause IDX.DT.empty current in
+ (* let bag, (alist, atable) =
let bag, alist =
- HExtlib.filter_map_acc (forward_simplify ctable) bag alist
+ HExtlib.filter_map_acc (simplify ctable) bag alist
in
- bag, (alist, List.fold_left IDX.index_unit_clause IDX.DT.empty alist)
- in
- debug "Simplified active clauses with fact";
+ bag, (alist, List.fold_left IDX.index_clause IDX.DT.empty alist)
+ in*)
+ debug (lazy "Simplified active clauses with fact");
(* We superpose active clauses with current *)
let bag, maxvar, new_clauses =
List.fold_left
bag, maxvar, newc @ acc)
(bag, maxvar, []) alist
in
- debug "First superpositions";
- (* We add current to active clauses so that it can be *
- * superposed with itself *)
+ debug (lazy "First superpositions");
+ (* We add current to active clauses so that it can be *
+ * superposed with itself *)
let alist, atable =
- current :: alist, IDX.index_unit_clause atable current
+ current :: alist, IDX.index_clause atable current
in
- debug "Indexed";
- let fresh_current, maxvar = Utils.fresh_unit_clause maxvar current in
- (* We need to put fresh_current into the bag so that all *
- * variables clauses refer to are known. *)
- let bag, fresh_current = Utils.add_to_bag bag fresh_current in
- (* We superpose current with active clauses *)
+ debug (lazy "Indexed");
+ let fresh_current, maxvar = Clauses.fresh_clause maxvar current in
+ (* We need to put fresh_current into the bag so that all *
+ * variables clauses refer to are known. *)
+ let bag, fresh_current = Terms.add_to_bag fresh_current bag in
+ (* We superpose current with active clauses *)
let bag, maxvar, additional_new_clauses =
superposition_with_table bag maxvar fresh_current atable
in
- debug "Another superposition";
+ debug (lazy "Another superposition");
let new_clauses = new_clauses @ additional_new_clauses in
+ debug (lazy (Printf.sprintf "Demodulating %d clauses"
+ (List.length new_clauses)));
let bag, new_clauses =
- HExtlib.filter_map_acc (forward_simplify atable) bag new_clauses
+ HExtlib.filter_map_monad (simplify atable maxvar) bag new_clauses
in
- debug "Demodulated new clauses";
+ debug (lazy "Demodulated new clauses");
bag, maxvar, (alist, atable), new_clauses
;;
+ let prof_ir = HExtlib.profile ~enable "infer_right";;
+ let infer_right bag maxvar current t =
+ prof_ir.HExtlib.profile (infer_right bag maxvar current) t
+ ;;
+
let infer_left bag maxvar goal (_alist, atable) =
- (* We superpose the goal with active clauses *)
- let bag, maxvar, new_goals =
+ (* We superpose the goal with active clauses *)
+ if (match goal with (_,_,_,[],_) -> true | _ -> false) then bag, maxvar, []
+ else
+ let bag, maxvar, new_goals =
superposition_with_table bag maxvar goal atable
in
- (* We demodulate the goal with active clauses *)
+ debug (lazy "Superposed goal with active clauses");
+ (* We simplify the new goals with active clauses *)
let bag, new_goals =
List.fold_left
(fun (bag, acc) g ->
- let bag, g = demodulate bag g atable in
- bag, g :: acc)
+ match simplify_goal ~no_demod:false maxvar atable bag [] g with
+ | None -> assert false
+ | Some (bag,g) -> bag,g::acc)
(bag, []) new_goals
in
+ debug (lazy "Simplified new goals with active clauses");
bag, maxvar, List.rev new_goals
;;
- end
-
-
+ let prof_il = HExtlib.profile ~enable "infer_left";;
+ let infer_left bag maxvar goal t =
+ prof_il.HExtlib.profile (infer_left bag maxvar goal) t
+ ;;
+ end